PR target/60280

	* tree-cfgcleanup.c (tree_forwarder_block_p): Protect loop
	preheaders and latches only if requested.  Fix latch if it
	is removed.
	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Set
	LOOPS_HAVE_PREHEADERS.

	PR target/60280
	* gnat.dg/renaming5.adb: Change to two expected gotos.
	* gcc.dg/tree-ssa/pr21559.c: Change back to three expected
	jump threads.
	* gcc.dg/tree-prof/update-loopch.c: Check two "Invalid sum"
	messages for removed basic block.
	* gcc.dg/tree-ssa/ivopt_1.c: Fix unreliable scanning string.
	* gcc.dg/tree-ssa/ivopt_2.c: Ditto.
	* gcc.dg/tree-ssa/ivopt_3.c: Ditto.
	* gcc.dg/tree-ssa/ivopt_4.c: Ditto.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@208165 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 18 insertions, 3 deletions

diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index 922ae0d82a6..b5c384b902c 100644
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -308,14 +308,24 @@ tree_forwarder_block_p (basic_block bb, bool phi_wanted)
   if (current_loops)
     {
       basic_block dest;
-      /* Protect loop latches, headers and preheaders.  */
+      /* Protect loop headers.  */
       if (bb->loop_father->header == bb)
 	return false;
-      dest = EDGE_SUCC (bb, 0)->dest;
 
+      dest = EDGE_SUCC (bb, 0)->dest;
+      /* Protect loop preheaders and latches if requested.  */
       if (dest->loop_father->header == dest)
-	return false;
+	{
+	  if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)
+	      && bb->loop_father->header != dest)
+	    return false;
+
+	  if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)
+	      && bb->loop_father->header == dest)
+	    return false;
+	}
     }
+
   return true;
 }
 
@@ -497,6 +507,11 @@ remove_forwarder_block (basic_block bb)
       set_immediate_dominator (CDI_DOMINATORS, dest, dom);
     }
 
+  /* Adjust latch infomation of BB's parent loop as otherwise
+     the cfg hook has a hard time not to kill the loop.  */
+  if (current_loops && bb->loop_father->latch == bb)
+    bb->loop_father->latch = dest;
+
   /* And kill the forwarder block.  */
   delete_basic_block (bb);